/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.search.aggregations.bucket.histogram;

import org.opensearch.common.collect.List;
import org.opensearch.index.query.QueryShardContext;
import org.opensearch.search.aggregations.Aggregator;
import org.opensearch.search.aggregations.AggregatorFactories;
import org.opensearch.search.aggregations.AggregatorFactory;
import org.opensearch.search.aggregations.BucketOrder;
import org.opensearch.search.aggregations.CardinalityUpperBound;
import org.opensearch.search.aggregations.support.CoreValuesSourceType;
import org.opensearch.search.aggregations.support.ValuesSourceAggregatorFactory;
import org.opensearch.search.aggregations.support.ValuesSourceConfig;
import org.opensearch.search.aggregations.support.ValuesSourceRegistry;
import org.opensearch.search.internal.SearchContext;

import java.io.IOException;
import java.util.Map;

/**
 * Constructs the per-shard aggregator instance for histogram aggregation.  Selects the numeric or range field implementation based on the
 * field type.
 *
 * @opensearch.internal
 */
public final class HistogramAggregatorFactory extends ValuesSourceAggregatorFactory {

    private final double interval, offset;
    private final BucketOrder order;
    private final boolean keyed;
    private final long minDocCount;
    private final DoubleBounds extendedBounds;
    private final DoubleBounds hardBounds;

    static void registerAggregators(ValuesSourceRegistry.Builder builder) {
        builder.register(HistogramAggregationBuilder.REGISTRY_KEY, CoreValuesSourceType.RANGE, RangeHistogramAggregator::new, true);

        builder.register(
            HistogramAggregationBuilder.REGISTRY_KEY,
            List.of(CoreValuesSourceType.NUMERIC, CoreValuesSourceType.DATE, CoreValuesSourceType.BOOLEAN),
            NumericHistogramAggregator::new,
            true
        );
    }

    public HistogramAggregatorFactory(
        String name,
        ValuesSourceConfig config,
        double interval,
        double offset,
        BucketOrder order,
        boolean keyed,
        long minDocCount,
        DoubleBounds extendedBounds,
        DoubleBounds hardBounds,
        QueryShardContext queryShardContext,
        AggregatorFactory parent,
        AggregatorFactories.Builder subFactoriesBuilder,
        Map<String, Object> metadata
    ) throws IOException {
        super(name, config, queryShardContext, parent, subFactoriesBuilder, metadata);
        this.interval = interval;
        this.offset = offset;
        this.order = order;
        this.keyed = keyed;
        this.minDocCount = minDocCount;
        this.extendedBounds = extendedBounds;
        this.hardBounds = hardBounds;
    }

    public long minDocCount() {
        return minDocCount;
    }

    @Override
    protected Aggregator doCreateInternal(
        SearchContext searchContext,
        Aggregator parent,
        CardinalityUpperBound cardinality,
        Map<String, Object> metadata
    ) throws IOException {
        return queryShardContext.getValuesSourceRegistry()
            .getAggregator(HistogramAggregationBuilder.REGISTRY_KEY, config)
            .build(
                name,
                factories,
                interval,
                offset,
                order,
                keyed,
                minDocCount,
                extendedBounds,
                hardBounds,
                config,
                searchContext,
                parent,
                cardinality,
                metadata
            );
    }

    @Override
    protected Aggregator createUnmapped(SearchContext searchContext, Aggregator parent, Map<String, Object> metadata) throws IOException {
        return new NumericHistogramAggregator(
            name,
            factories,
            interval,
            offset,
            order,
            keyed,
            minDocCount,
            extendedBounds,
            hardBounds,
            config,
            searchContext,
            parent,
            CardinalityUpperBound.NONE,
            metadata
        );
    }
}
